Manually operable thermostatic switch assembly



.Aug. 29, 1950 R BEAN 2,520,874

MANUALLY OPERABLE THERMOSTATIC SWITCH ASSEMBLY Original Filed Oct. 19, 1942 :hmcntor Frank Rob erz Be an Gttorneg Patented Aug. 29, 1950 MANUALLY OPERABLE THERMOSTATIC SWITCH ASSEMBLY Frank Robert Bean, Rochester, N. Y., assignor to Fasco Industries, Inc., Rochester, N. Y., a corporation of New York Original application October 19, 1942, Serial No.

Divided and this application Novemm 'z, 1949, Serial No. 126,029

4 Claims. (01. 200-113) The present application is a division of my copending application Serial No. 462,504, flied ctober 19, 1942 for "Manually Operable Thermostatic switch Assembly. The present invention relates to a manually operable thermostatic switch assembly and more particularly to the combination with a thermostatic switch assembly of a means movable to two or more positions and which may be manually operated to re-set or return the thermostatic element of a thermostatic switch to a' closed or operative position.

The us of thermostatically operated switches to interrupt an electric circuit under predetermined and/or abnormal conditions is well known. However, it is also necessary and desirable to manually control the position of the switch element of such an assembly and move the same to an on and/or oil position irrespective of the load conditions in the circuit including the thermostatic element.

The primary object of the present invention is the provision of a manually operable member movable to either of two positions and for rendaring the thermostatic element of a thermostatic switch assembl operative when said memher is moved to one of its positions.

Another object of the invention is the combination with a switch means including a snap acting thermostatic switch arm, of a manually operable re-set member for permitting or compelling return of said switch arm to a closed position.

A further object is the combination with a switch means having a normally closed thermostatic switch arm, of a. manually operabe resetting member which is also movable to a position to render said switch inoperative.

Still another object is the provision on the manually operable means of a stop or an abutment for modifying the thermal operation of a thermostatic switch assembly.

A still further object of the invention is a switch assembly having a normally closed-thermostatic switch arm and manual operable means including an intermediate means for holding said switch arm in open position. I

The foregoing and other objects of the invention are embodied in the combination of a thermostatic switch assembly having a normally closed switch arm, a manually operable member movable at least to either of two positions, and an intermediate means operatively connected to said manually movable member. The uses and advantages of such thermostatic switch assembly may be increased by providing a stop or abut:

- 2 ment to limit the opening movement of the thermostatic switch arm.

Reference is hereby made to the accompanying drawings wherein similar reference characters designate similar elements and wherein:

Fig. 1 is a vertical longitudinal section of a thermostatic switch assembly including a manually operable member according to the invention.

Fig. 2 is a vertical transverse section taken on the line 2-2 of Fig. 1.

Fig. 3 is a perspective detail of a normally r turning thermostatic switch arm.

In general the manually operable thermostatic switch assembly according to the invention comprises a switch means including a thermostatic switch arm, a manually operable member, and an intermediate member. The manually operable member is movable to at least two positions and is operatively connected to said intermediate member which determines the operability of the switch arm according to the position of the manually operabe member and/or the thermal condition of the thermostatic switch arm. Said switch assembly may be mounted upon an instrument panel or similar support by means of a mounting plate carrying a casing and an insulating base.

The switch assembly may be mounted upon an instrument panel or similar support by means of glrnounting plate 20 which is provided with holes to said plate 20 in any suitable manner as by spot Welding. A base 24 of any suitable insulating material covers the open side of said casing 22. A pair of terminal members 26 are mounted on the base 24 "and one of said terminal members 26 has its inner end fastened to base 24 by a rivet 21, the head of which constitutes a contact 28. The other terminal member 26 has its inner end fastened to base 24 by a rivet 29" having an enlarged head 30 on which a thermostatic switch arm 3| is mounted. The other ends of said terminal members 28 may extend through the base 24 for attachment to external conductors or wires of the circuit to be controlled.

The thermostatic switch arm 3| is preferably composed of bimetallic sheet material and is of the snap acting type. Such a switch arm 3| is best shown in Fig. 3 and may be provided with a hole 32 for receiving a stud 33 which may be spun or riveted over to hold said switch arm 3| on head 30. The switch arm 3! is provided with a pair of diverging slots 34 and is deformed with gathered portions 35 at the outer ends of each slot 34 so that said arm 31 is dished or curved longitudinally as shown in Fig. 1 and curved A casing 22 having an open side is fastened transversely as shown in Fig.1 Switch arm I carriesacontactstandisarrangedsothataaid contact a normally engages contact II. An integral projection 31 extends from th free end of switch armll for a purpose tobe later elplained. I

The intermediate member comprises a spring arm HI having one end fastened to casing 32 by rivets H2 and having its other end fastened by a rivet ill to an insulating plate Ill. A stirber including a pivoted lever movable from a cenrup member I II is fastened to plate Ill by a rivet 1 H8, has one end In for engaging the under surface of projection 31 on switch arm 8i and has another end Ill for eng ging the upper surface of switch arm ii. The manually operable member comprises a ball Ill mounted in hemisspherical forminss ill and III respectively in mounting plate It and the top of casing 22, a handle I22 extending through a slot III in forming in and threaded into ball ill, and a threaded stud I23 extending through a slot III in forming ill. A U-shaped member I has a pin Ill extending between the legs thereof and upon which pin I2! is mounted a roller I". Said member I24 is screwed onto stud I13 and the spring arm I i I extends between roller ill andthe central portion of member I24.

The normal action of spring arm Ill on roller I26 normally moves handle I22 to its intermediate position shown in Fig. 1. Current above the critical value in thermostatic switch arm 3| will cause the same to open and separate the contacts 28 and 86 but the opening movement of switch arm 3| is limited by end III to reduce the time for thermostatic switch arm II to cool and return to its normally closed position. The spring arm III is comparatively strong with respect to switch arm 3| so that abutment thereof against end ill does not move said spring arm Hi. How. ever, when it is desired to move said switch arm II to open position or to hold the same in open position, the manually operable member or handie In is swung in either direction whereupon roller I2 raises spring arm ill and end 1 of member H5 engages the under surface of projection 31 to lift switch arm 3i and open contacts 28 and 38. As soon as the handle I2! is released the intermediate member returns to its normal position and the switch arm II either returns to its normally closed position or is intermittently opened if there is an abnormal current in the circuit.

In the switch assembly shown, the mechanical opening of the snap acting thermostatic switch arm 3| by the intermediate and manually operable members causes said switch arm II to assume a position like that caused by thermal opening thereof in that the curvature of said switch arm II is reversed. Mechanical opening of said tral position to an extreme position, and an intermediate member normally in a position corresponding to the centre: position of said lever,

carrying a stop for limitin the thermal operation of said arm when said intermediate member is in normal position, and alsoggarrying an abutment for moving said arm to opfeh position when said lever is moved to extreme position for moving said intermediate member out of normal position.

2. In a circuit breaker, a support, relatively fixed and movable contacts on said support. means responsive to predetermined conditions for automatically moving said movable contact out of engagement with said fixed contact, manually operable actuating means for said movable contact having lost motion therewith, whereby at one position of said actuating means said movable contact is movable to open and close the circuit by movement relative to said actuating means, and resilient means biasing said actuating means to said one position.

3. In a circuit breaker, a support, relatively fixed and movable contacts on said support, means responsive to predetermined conditions for automatically moving said movable contact out of engagement with said fixed contact, manually operable actuating means for said movable contact, said actuating means mounted on said support for movement into engagement with said movable contact to actuate the same, andresilient means normally maintaining said actuating means spaced from said movable contact and out of the range of automatic movement thereof.

4. In a circuit interrupter, a support, a contact mounted on said support, a bimetal element mounted on said support, said element having a portion adapted to engage said contact and automatically movable out of engagement in response to the passage of currents above a predetermined value through the circuit, manually operable actuating means for said element, said actuating means mounted on said support for movement into engagement with said element to actuate the same, and resilient means normally maintaining said actuating means spaced from said element and out of the range of automatic movement thereof.

FRANK ROBERT BEAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES. PATENTS Name Date Immel Nov. 11, 1941 Parkhurst et al. May 16, 1944 Lee Apr. 17, 1945 Number 

